Nine years and the Atlantic Ocean separate these reeds and violin duos from one another, but both are equally concerned with exploring the limits of collaboration, unfettered by genre expectations.

Piotr Michalowski on soprano saxophone and bass clarinet and Mike Khoury on violin, both from the Detroit area, prefer shorter forms, dividing their textural improvisations among 10 tracks which together add up to about 40 minutes of music. Offering the equivalent of a novel compared to Reason Sound - Sound Reason’s collection of sonic short stories, London-area soprano and alto saxophonist Trevor Watts and violinist Peter Knight take nearly 56½ minutes on Reunion: Live in London to explore virtually every variation, oscillation and texture that can be wrung from their respective instruments. Both duos display their work to similarly miniscule audiences in the live portions

Simpatico here, Watts and Knight have disparate musical backgrounds which feed the inspiration for Reunion. Classically-trained Knight is best-known for his tenure with Steeleye Span, which mixed traditional English folks songs and rock music. Watts led bands such as Moiré Music and Amalgam which blended so-called World music and jazz. For years in the 1960s and 1970s he was also part of the vastly influential Spontaneous Music Ensemble, whose completely improvised programs of microtonal tunings and intervals melded with dislocated rhythms influenced subsequent generations of improvisers such as Michalowski and Khoury.

Such reliance on chance and usual tunings doesn’t negate the possibilities for close concordance however, and throughout Reason Sound - Sound Reason each player creates his version of discordant lines before meeting for unison harmonies. Khoury concentrates on woody spiccato and sul ponticello scraping, while Michalowski’s strategy depends on his instrument. On bass clarinet lunging chalumeau breaths predominate, while the soprano saxophone is oriented towards liquid stops and percussive tongue slaps.

There are even points at which the fiddler begins a piece with near-conventional romantic bowing, while the reedist stops, starts and spurts glottal punctuation. Then, almost transforming themselves into actors in a Sci-Fi flick about trans-mutating identities, Khoury’s strokes get spikier and harsher as Michalowski’s output solidifies into bagpipe-like exhalation. On other tracks an intermezzo finds the violinist splitting his own musical personality with tremolo strokes and unforced harmonies arriving at the same time as pizzicato string pops and snaps. Beside him, diaphragm-vibrated rumbles from the bass clarinet dig deeper into subterranean timbres until they intersect in mid-range with Khoury’s output.

Among the distinct and distant cries and echoes is the stand-out work on “Swish”. Contrapuntally the two mate hunting horn sonority and fierce stropping strings until Michalowski dislocates the nodes into partials with reed bites and key percussion. Plucking his violin with mandolin-like licks, Khoury follows suit with abstracting harmonies. Final unity depends on circular breathing from the reedist and double-stopping filigree from the fiddler.

Less abstract than the Michalowski-Khoury duets, Watts and Knight create an interface more closely related to the expected sonic properties of the saxophone and the violin. Still, this 1999 recording inserts additional timbres as well. Extended techniques such as Watts’ flutter-tonguing and Knight’s long-lined adagios not only adumbrate the duo in the direction of rondo effects, but introduce further non-European musical echoes. For instance within the overlapping harmonies, there are points at which Watts’ soprano takes on vaguely musette-like tones and elsewhere Knight’s delicate strumming makes it appear as if he’s playing an Elizabethan lute. In those cases the gentling timbres work the desired effect on Watts and soon the saxophonist’s tonality takes on bel canto purity.

Other spots enhance and diffuse the timbres further eastward. As well as Old-Timey claw-hammer banjo licks, Knight’s pizzicato twangs and measured silences at various times resemble sounds emanating from an erhu, a kora or a guimbri. For his part, Watts’ staccato peeps, basso honks and Aylerian trills ran the gamut of tone references including the fluting tones of a dizi, the nasal qualities of a suona and the zig-zag trills of a raita. Unexpected polyphonic combinations arise spontaneously as well, such as when Watt’s reversion to neo-Bop chirps on the alto saxophone has Knight, arco, modulating up the scale to outline a contrapuntal Renaissance-directed pastoral melody. Elsewhere, sharp reed variants are almost minimized to silence and tongue slaps by continuous sul tasto bowing, while on the other hand supple glissandi and spacious obbligatos help shape Knight’s swelling bowing into near-Impressionism. Playing double counterpoint, the two improvisers conjure up intimations of minaret cries, ceremonial parades and courtly ballads.

This mixture of quasi-sacred and quasi-secular harmonies also feature in individual codas as Knight’s close-set glissandi finally remind the listener he’s playing a modern violin and Watts’ bluesy, exaggerated Pete Brown-like vibrato cements his experiments with earlier jazz. Knight played in a couple of Watts’ bands in the 1980s, but the CD is called Reunion since this gig followed a long hiatus. Recently the two have reunited once again and with additional familiarity may be encompassing even more abstraction. Perhaps in 2009 they may head for territory staked out by Khoury and Michalowski.

In terms of these duo CDs, however, while related, neither could be mistaken for the other. Still each offers equally inventive sounds to investigate.